GAZA CITY, Gaza Strip (AP) — An Israeli airstrike in Gaza on Friday killed the commander of the militant group behind the abduction of Gilad Schalit, an Israeli soldier who was held captive for more than five years and freed in a prisoner swap for more than 1,000 Palestinians.

The midday attack marked the highest profile Israeli strike against the coastal strip in several months and immediately set off a violent escalation after a period of relative calm.

Various Palestinian militant groups fired dozens of rockets, some deep into Israeli territory, prompting Israel to issue warnings to its residents to stay indoors. The Israeli military pounded several rocket launching cells in Gaza. In all, 10 Palestinian militants were killed in Israeli airstrikes, and one Israeli citizen was seriously wounded by the Palestinian rocket fire.

The Israeli military said it initially targeted Zuhair al-Qaissi, the commander of the armed wing of the Popular Resistance Committee, a large militant group closely aligned with Gaza’s Hamas rulers. The explosion tore apart al-Qaissi’s blue sedan and killed his son-in-law, Mahmoud Hanini — himself a top PRC field commander. Another low ranking Gaza militant also died.

Hours later, Israeli military killed two more militants that it said were about to launch rockets. After midnight, Palestinian officials said another five were killed in and around Gaza City.

Palestinian witnesses said Israeli drones were seen hovering above just moments before al-Qaissi’s vehicle burst into flames. They said the blast was so fierce that al-Qaissi’s head detached as a result.

The Israeli military said al-Qaissi was plotting an infiltration attack into Israel similar to the one he orchestrated in August from the Sinai peninsula that killed eight Israelis and injured 40 more.

The armed wing of the Popular Resistance Committee is responsible for dozens of deadly attacks against Israelis in recent years and its members are among the most active rocket launchers from Gaza into Israel.

The Israeli military said al-Qaissi was also in charge of transferring funds from the Lebanese militant group Hezbollah to other militant groups in Gaza.

But the group is mostly known for carrying out the brazen 2006 abduction of Schalit and holding on to him for more than five years until he was freed in a massive prisoner swap last year.

Israel’s agreement to release 1,027 Palestinians for Schalit was the most lopsided swap in the country’s history. Hundreds of those released have vowed to resume violence against Israel.

Israel often targets Gaza militants it says are preparing attacks, but tensions have been relatively calm in recent months with Israel mostly targeting smuggling tunnels from Egypt and refraining from attacking individuals. Al-Qaissi, who is also known as Abu Ibrahim, is the highest profile casualty in Gaza since his predecessor, Kamal Nairab, was killed seven months ago in similar fashion.

The military said Palestinian militants had fired some 50 rockets and mortar shells at Israel over the past two months, causing no casualties and little damage.

In contrast, some three dozen were fired Friday alone — with Israel’s Iron Dome missile defense system intercepting five, the military said.

Gaza militants promised many more would come.

“The coward Zionists have committed an ugly crime and they know the price that they are going to pay,” said a PRC spokesman, who goes by the pseudonym Abu Mujahid.

“We call on our fighters to respond to the Zionist enemy with all our strength,” he said. “We shall avenge our leader and the response, God willing, will be equal to the size of the heinous crime.”

The Israeli military insisted it did not want an escalation but said it was “prepared to defend the residents of Israel.”

But it appeared to be getting ready for the worst, issuing a warning to Israeli residents living within 40 kilometers (25 miles) from Gaza to stay close to home Friday night and refrain from holding major outdoor events Saturday.

Israel said Hamas was using other groups to carry out attacks in its place and warned that Gaza’s rulers “will bear the consequences of these actions” if an escalation took place.

Mere hours later, Israel struck two more Gaza militants preparing to fire rockets. Gaza Health Ministry official Adham Abu Salmiya confirmed two were killed east of Gaza City. The Islamic Jihad said the dead men were its members.